The present invention relates to brake control systems and pertains particularly to a tamper-proof secondary control system for a fail-safe brake system.
Many large vehicles, especially earthmoving vehicles, employ fail-safe brake systems wherein the brakes are spring applied and fluid pressure released. Upon failure of the fluid pressure, the brakes are automatically applied and the vehicle cannot be moved until an auxiliary source of pressure is made available to release the brakes.
Some vehicles are provided with an auxiliary system so that the operator is merely required to shift a valve to move or continue operation of the vehicle for a short period of time. This arrangement allows the vehicle to be moved if necessary for repairs or the like. One problem with this arrangement is that vandals may open the auxiliary valve and move the vehicles or drain the auxiliary supply.